BUS BAR IN AFE COMMON DC-LINK 

MOTOR DRIVERS

AFE is abbreviation of Active Front End.

Consisting of power components which include IGBT, AFE is equivalent to an inverter, from view point of function. 

However different from inverter, AFE links at power inlet side of system, and output DC, so it is called the 'FRONT END'.  

Differentiated from typical DIODE or SCR (abbreviation of Silicon Controlled Rectifier) technology, the 'ACTIVE' of AFE means that AFE not only converts AC to DC negatively, but also masters control capabilities. 

In detail, AFE is capable of eliminating High Harmonics, improving Power Factor, subjecting nothing from grid fluctuations. 

AFE has excellent dynamic characteristics. In AFE common DC bus system, High Harmonics could be eliminated down to zero, while Power Factor be improved to one. 

In AFE common DC bus system, AFE supplies DC for multi-motor AC speed regulation module. Speed regulation inverters connect with common DC bus system directly.    

While multi-motor AC speed regulation module running, inverters are driven by power which is supplied from DC bus. While the system is under power generation status, generation will input back to the grid directly via common DC bus and AFE. 

AFE common DC bus technology leads to power saving, improve equipment operation reliability, mitigate system maintenance and minimize system size, etc.

Both high power density, high reliability, and low inductance are key criteria to holistic inverter designs. 

In high power scenarios, which include but not limit locomotive traction, photovoltaic, wind power inverter, it is necessary to minimize both concentrated loss and stray-load loss in the course of power transmission. 

One of the ongoing challenges toward inverter systems development is to customize integrated laminated bus bar. Laminated bus bar must be robust enough to withstand high voltage and high current. 

In the mean time, laminated bus bar must be low inductance to minimize switching loss of the both wind inverter and wind converter. 

Another key to bus bar design is to integrate laminated bus bar with typical film capacitors together. 

Leveraged by integration design, it reduces effectively Equivalent Series Inductance (ESL), reduces equipment size, and increases power density.